催化反应对低磨料浓度化学机械平坦化的影响

通过低磨料浓度下催化反应对铜膜抛光速率的影响,证实了纳米SiO2胶体作为催化反应物可以极大地提高铜膜表面的化学反应速率。通过浸泡在不同磨料浓度抛光液中的铜电极表面腐蚀电位和腐蚀电流数值,进一步证实了催化反应能够加速凹处钝化膜的生成,并确定了在静态腐蚀条件下催化反应速率转换临界点所对应的纳米SiO2溶胶浓度为0.1vol%和1vol%。根据催化反应对铜晶圆各平坦化参数的影响,确定了低磨料CMP的最佳纳米SiO2溶胶浓度为0.3vol%,此时铜晶圆的抛光速率、台阶消除量、平坦化效率、碟形坑高度和腐蚀坑高度分别为535nm/min、299nm、56%、103nm和19nm。     

化工中间体乙二醛的最佳合成工艺探索

乙二醛作为一种重要的化工中间体,用途涉及到诸多行业,但是其合成工艺一直不太成熟。本文通过研究控制乙二醛合成反应的因素对乙二醛产率和产率选择性的影响,得出了乙醛硝酸氧化法制备乙二醛的最佳工艺流程,并详细的分析了各因素对主副反应的影响。     

铜膜高去除速率 CMP 碱性抛光液的研究及其性能测定

目的探索适合于TSV技术的最佳CMP工艺。方法在碱性条件下,利用碱性FA/O型鳌合剂极强的鳌合能力,对铜膜进行化学机械抛光,通过调节抛光工艺参数及抛光液配比,获得超高的抛光速率和较低的表面粗糙度。结果在压力27.56 kPa,流量175 mL/min,上下盘转速105/105 r/min,pH=11.0,温度40℃,氧化剂、磨料、螯合剂体积分数分别为1%,50%,10%的条件下,经过CMP平坦化,铜膜的去除速率达2067.245 nm/min,且表面粗糙度得到明显改善。结论该工艺能获得高抛光速率。     

粗糙度和尖峰高度对粗糙铜晶圆表面化学反应动力学参数的影响

根据液固化学反应特性和欧几里得有效面积公式,建立了适用于粗糙晶圆表面的化学反应动力学方程,得到了不同晶圆表面的化学反应速率常数和化学机械平坦化(CMP)前后晶圆质量差。根据晶圆表面不同位置的lg(RMS height)lgx拟合直线斜率和截距的平均值,得到了每个晶圆表面的分形维数与尺度系数,进一步得到了铜膜化学反应分级数。通过分析晶圆表面分形维数对化学反应动力学参数的影响,可以得出： 当表面分形维数为2.917时,铜膜的化学反应分级数为1,此时铜膜的络合反应过程中的所有瞬时反应数量达到最小值。最后的验证试验表明： 晶圆表面分形维数越大,CMP后尖峰消除量越大,即铜膜表面化学反应速率越快;晶圆表面分形维数越小,CMP后粗糙度下降越明显,即铜膜表面化学反应均匀性越好。     

乙醇对低磨料CMP过程中铜膜凹凸处去除速率选择性的影响

根据相似相容原理,在低磨料浓度CMP过程中,利用乙醇对多羟多胺螯合剂的降黏特性来提高铜膜表面凹凸处抛光速率的选择性。根据抛光液中各组分浓度对动态和静态条件下铜膜去除速率的影响获得乙醇加入量的最大值;通过螯合剂、氧化剂与乙醇对动静态条件下铜膜去除速率的相互作用关系来确定各组分的最佳浓度。最终得出当各组的体积分数为:磨料0.5%,螯合剂10%,H2O20.5%,乙醇1%时,铜膜表面拥有最大的凸处和凹处速率比。在MIT 854铜布线片上进行平坦化试验,结果表明:该抛光液能够很大程度的减小布线表面的高低差,拥有较强的平坦化能力。红外光谱检测结果表明:在CMP过程中,铜膜表面不会生成副产物乙酸乙酯。上述结果进一步证实了该抛光液的实用性。     

乙二醛合成反应动力学研究

本文通过对乙二醛合成反应动力学的研究,得到了不同温度下各反应的化学反应速率常数。根据阿伦尼乌斯方程对上述化学反应速率常数进行线性拟合分析,最终得到了不同阶段化学反应速率的活化能表达式,具体表达为:乙二醛的净生成速率rc=exp(53318.597/RT-27.05)CACB-exp(-13.918/RT+0.006)CCCB;乙醛酸的净生成速率rD=exp(-13.918/RT+0.006)CCCB-exp(-361 160.16/RT+156.56)CDCB。     

基于SiO2溶胶的稳定性的Cu/SiO2催化体系在化学机械抛光中的应用研究

There is a lot ofhydroxyl on the surface ofnano SiO2 sol used as an abrasive in the chemical mechanical planarization （CMP） process, and the chemical reaction activity of the hydroxyl is very strong due to the nano effect. In addition to providing a mechanical polishing effect, SiO2 sol is also directly involved in the chemical reaction. The stability of SiO2 sol was characterized through particle size distribution, zeta potential, viscosity, surface charge and other parameters in order to ensure that the chemical reaction rate in the CMP process, and the surface state of the copper film after CMP was not affected by the SiO2 sol. Polarization curves and corrosion potential of different concentrations of SiO2 sol showed that trace SiO2 sol can effectively weaken the passivation film thickness. In other words, SiO2 sol accelerated the decomposition rate of passive film. It was confirmed that the SiO2 sol as reactant had been involved in the CMP process of copper film as reactant by the effect of trace SiO2 sol on the removal rate of copper film in the CMP process under different conditions. In the CMP process, a small amount of SiO2 sol can drastically alter the chemical reaction rate of the copper film, therefore, the possibility that Cu/SiO2 as a catalytic system catalytically accelerated the chemical reaction in the CMP process was proposed. According to the van＇t Hoff isotherm formula and the characteristics of a catalyst which only changes the chemical reaction rate without changing the total reaction standard Gibbs free energy, factors affecting the Cu/SiO2 catalytic reaction were derived from the decomposition rate of Cu （OH）2 and the pH value of the system, and then it was concluded that the CuSiO3 as intermediates of Cu/SiO2 catalytic reaction accelerated the chemical reaction rate in the CMP process. It was confirmed that the Cu/SiO2 catalytic system generated the intermediate of the catalytic reaction （CuSiO3） in the CMP process through the removal rate of copper film, infrared spectrum and AFM diagrams in different pH conditions. FinalLy it is concluded that the SiO2 sol used in the experiment possesses stable performance; in the CMP process it is directly involved in the chemical reaction by creating the intermediate of the catalytic reaction （CuSiO3） whose yield is proportional to the pH value, which accelerates the removal of copper film.     

Electrochemical investigation of copper chemical mechanical planarization in alkaline slurry without an inhibitor

This work investigates the static corrosion and removal rates of copper as functions of H202 and FA/OIIconcentration, and uses DC electrochemical measurements such as open circuit potential （OCP）, Tafel ana- lysis, as well as cyclic voltammetry （CV） to study HaOa and FA/OIIdependent surface reactions of Cu coupon electrode in alkaline slurry without an inhibitor. An atomic force microscopy （AFM） technique is also used to measure the surface roughness and surface morphology of copper in static corrosion and polishing conditions. It is shown that 0.5 vol.% H202 should be the primary choice to achieve high material removal rate. The electro- chemical results reveal that the addition of FA/O II can dissolve partial oxide film to accelerate the electrochemical anodic reactions and make the oxide layer porous, so that the structurally weak oxide film can be easily removed by mechanical abrasion. The variation of surface roughness and morphology of copper under static conditions is consistent with and provides further support for the reaction mechanisms proposed in the context of DC electro- chemical measurements. In addition, in the presence of H202, 3 vol.% FA/O II may be significantly effective from a surface roughness perspective to obtain a relatively flat copper surface in chemical mechanical planarization （CMP） process.     

多层铜布线CMP后表面残留CuO颗粒的去除研究

This article introduces the removal technology of CuO particles on the post CMP wafer surface of multi-layered copper. According to the Cu film corrosion curve with different concentrations of HEO2 and the effect curve of time on the growth rate of CuO film, CuO film with the thickness of 220 nm grown on Cu a surface was successfully prepared without the interference of CuC12.2H20. Using the static corrosion experiment the type of chelating agent （FA/O II type chelating agent） and the concentration range （10-100 ppm） for CuO removal was determined, and the Cu removal rate was close to zero. The effect of surfactant on the cleaning solution properties was studied, and results indicated that the surfactant has the effect of reducing the surface tension and viscosity of the cleaning solution, and making the cleaning agent more stable. The influence of different concentrations of FA/O I type surfactant and the mixing of FA/O II type chelating agent and FA/O I type surfactant on the CuO removal effect and the film surface state was analyzed. The experimental results indicated that when the concentration of FA/O I type surfactant was 50 ppm, CuO particles were quickly removed, and the surface state was obviously improved. The best removal effect of CuO on the copper wiring film surface was achieved with the cleaning agent ratio of FA/O II type chelating agent 75 ppm and FA/O I type surfactant 50 ppm. Finally, the organic residue on the copper pattern film after cleaning with that cleaning agent was detected, and the results showed that the cleaning used agent did not generate organic residues on the film surface, and effectively removes the organic residue on the water.